1. Field of the Invention
The present invention is directed to a check valve with improved mixing effectiveness of the primary flow through the valve with the receiving body of water or other fluid.
2. Description of Related Art
Traditional “duckbill” type check valve nozzles have a single inlet and a single discharge outlet opening and are primarily designed to prevent reverse flow. See, for example, U.S. Pat. No. 6,367,505 to Raftis et al. entitled “Check Valve with Oversized Bill.” However, they are often used for other reasons such as providing a controlled pressure drop as a function of flow rate in the forward direction or, in diffuser systems, to reduce variation in the discharge jet velocity as a function of flow rate. Such traditional “duckbill” type check valve nozzles work well in these applications because they exhibit a linear relationship between headloss (pressure drop) across the check valve nozzle and flow rate when fluid is discharged through the check valve nozzle. In contrast, when fluid is discharged through a fixed orifice nozzle, the headloss (pressure drop) exhibits a “square law” relationship to the flow rate. This linear relationship between headloss and flow rate also makes traditional “duckbill” type check valve nozzles particularly useful for mixing systems because it provides a more consistent exit velocity as flow rate changes than a fixed orifice nozzle, i.e., exit velocity decreases less as flow rate decreases for a traditional “duckbill” check valve nozzle than for a fixed orifice nozzle. Therefore, the amount of mixing between the fluid discharged from the check valve nozzle and the receiving fluid remains more consistent.
In addition, the “duckbill” type check valve nozzle provides a flattened exit jet creating greater surface area than a conventional fixed circular orifice nozzle, which improves mixing.
While traditional “duckbill” check valve nozzles have found use as mixing nozzles, their mixing ability is limited. It is therefore an object of the present invention to provide a check valve nozzle with improved mixing capabilities.